Work study-150303084338-conversion-gate01

WORK STUDY
It is a generic term for those techniques,
method study and work measurement
which are used in the examination of
human work in all its context. And which
lead systematically to the investigation of
all the factors which affect the efficiency
and economy of the situation being
reviewed, in order to effect improvement
2

WORK STUDY
 Method study
 It is the systematic recording & critical examination
of existing and proposed ways of doing work, as a
means of developing and applying easier and more
effective methods and reducing cost
 Work measurement / Time study
 It is the application of techniques designed to
establish the time for a qualified worker to carry out
a specified job at a defined level of performance
4

WORK STUDY PROCEDURE
5
SELECT
RECORD
EXAMINE
DEVELOP
MEASURE
DEFINE
INSTALL
MAINTAIN

INFLUENCE OF METHOD & TIME STUDY IN
PRODUCTION ACIVITIES
6

WORK CONTENT
7
Basic work content
Excess work content

REASONS FOR EXCESS WORK CONTENT
8
A. Defects in design
B. Inefficient methods of manufacture
C. Short-comings of the mgt.
D. Work-man attributes

METHOD STUDY
10
It is the systematic recording & critical
examination of existing and proposed ways
of doing work, as a means of developing and
applying easier and more effective methods
and reducing cost

METHOD STUDY
11
Objectives
Critical examination of facts
Develop best possible solution
Eliminate unnecessary operations
Add value & Avoid delays
Optimize 3M

METHOD STUDY PROCEDURE
12
SELECT
RECORD
EXAMINE
DEVELOP
DEFINE
INSTALL
MAINTAIN

JOB SELECTION
13
Economic aspect
Technical aspect
Human aspect

RECORDING TECHNIQUES
15
CHARTS
Macro-motion charts
Micro-motion charts
DIAGRAMS
Flow & String diagrams
Cycle graph & Chronocycle graph

RECORDING TECHNIQUES - CHARTS
16
Primary Information required on the chart
Adequate description of activities
Chart for present or proposed method
Specific reference to when the activities
will begin & end
If applicable, time & distance scales
Name of person & date

17
Macro-motion charts
Operation/Outline process chart
Flow process chart
Multiple activity chart
Two handed process chart

18
Operation/Outline process chart
•Record major activities & inspections
•Operation & Inspection symbol used

21
Flow process chart
•Material type
•Man type
•Equipment type

25
Flow process chart usefulness:
•Reduce travel distance of man/material
•Avoid waiting time & unnecessary delays
•Reduce cycle time by combining or eliminating
operations
•Fix up the sequence of operations
•Relocate the inspection stages

26
Two handed process chart
(Operator process chart)
•Records activity of workers hand
•Representing sequence of manual activities
of the worker
•Studies work station layout & repetitive task
Inspection – touch/feel by hand is to be recorded
Storage – hand used as a grip or vice to hold the object

28
Multiple activity chart
•Activities of more than one subject (man or
equip.) are each recorded on a common time
scale to show their inter-relationship
•Study idle time of man & machines
•Determing number of machines handled by
one operator
•Determing number of operator required in
teamwork to perform given job

MICRO-MOTION STUDY
30
Micro-motion/Therbligs
Technique of recording and analyzing the
timing of basic elements of an operation
Developing best possible pattern of
movement; operator performing @ minimum
effort and fatigue, for repeated operations
Consists of taking motion pictures of the
operation with a clock in the picture (or with a
video camera running at a known speed)

MICRO-MOTION STUDY
31
Micro-motion/Therbligs
The speed of the camera used ranges from 960
to 1000 frames per minute. But faster cameras
may be used to study very fast hand motions or
complex operations.
Micromotion study should be used when it is
economical to do so (short cycle highly
repetitive operations, large volume production
or operation performed by a large number of
workers)

MICRO-MOTION STUDY
32
Therbligs

MICRO-MOTION STUDY
33
Therbligs
 Search (SH) – attempt to find an object using eyes or hand
 Find (F) – mental reaction at end of search
Select (ST) – choose among several objects in a group
 Grasp (G) – grasp an object
 Hold (H) – hold an object
Transport loaded (TL) – move an object with hand and arm
Transport empty (TE) – reach for an object
 Position (P) – position object in defined location
Assemble (A) – join two parts
 Use (U) – manipulate a tool
Disassemble (DA) – separate multiple parts that were previously joined
 Inspect (I) – determine quality of object
Pre-position (PP) – position object for next operation
Release load (RL) – release control of an object
Unavoidable delay (UD) – waiting due to factors beyond worker control
Avoidable delay (AD) – worker waiting
Plan (PN) – decide on an action
Rest (R) – resting to overcome fatigue

MICRO-MOTION STUDY
34
Micro-motion study involves the following steps:
1)Filming the operation to study
2)Analysis of the data from the films
3)Making recording of the data
(using SIMO chart)

35
MICRO-MOTION STUDY
SIMO chart format:
(SImultaneous MOtion cycle chart)

MICRO-MOTION STUDY
36
Provides a permanent record of motion study on films.
 A large number of operators can see the procedure at
any time even after the completion of motion study work.
 Films can easily reveal the difference between the
present and the proposed technique.
 Films can be demonstrated to large work force at any
desired speed.
 It provides very accurate time for each operation or
motion in comparison to stop watch time study.

MICRO-MOTION STUDY
37
It helps in making detailed and accurate analysis of the
prevailing technique.
To study the activities of the machine and the operator.
 To impart training to the workers or operators
regarding motion; economy so that unnecessary movement
by the workers may be avoided.
 To study the relationship between the activities of
operator and the machine.
To obtain motion time data for developing synthetic time
standards for various elements.

MEMO-MOTION STUDY
38
In memomotion study, the camera speed is at
60 or 100 frames per minute
It is a form of time lapsed cine-photography
Time interval lies b/w 1/2sec to 4sec
10 or 20 min. may be compressed into 1min

RECORDING TECHNIQUES - DIAGRAMS
39
Diagrams
Indicates the path of movement
Study of traffic & frequency over different
routes of plant
Identification of back-tracking & obstacles
during movements
Study of different layout plans & select
optimal layout

40
Flow Diagram
1)Layout of w/p is drawn to scale
2)Relative positions of m/c tools, work benches, etc
are marked
3)Path followed by the subject under study is traced
by drawing lines
4)Each movement is serially numbered and
indicated by arrow for direction
5)Different colors are used to denote different types
of movements

42
String Diagram
String/Thread is used to measure the distance
Records the pattern of movement of a worker
working within a limited area during a certain
period of time
Repetitive movements can be conveniently traced

43
String Diagram
1)Layout of the w/p or factory is drawn to scale on a
soft board
2)Pins are fixed into boards to mark the location of
work stations,
3)Pins are also driven at the turning point of the routes
4)A measured length of thread is taken to trace the
movement (path)
5)The distance covered by the object is obtained by
measuring the remaining part of the thread and
subtracting it from the original length

46
Cycle graph & Chronocycle graph
Both records the motion path of an
operator & requires filming equipment
Movements which are very fast and very
difficult for the human eye to trace are
traced by these techniques

47
Cycle graph
Indicates a permanent
record of the motion pattern
employed in the form of a
closed loop of continuous
line.
It does not indicate the
direction or speed of motion.

48
Chronocycle graph
Indicates short dashes of line spaced in proportion to
the speed of the body member photographed
Wide spacing would represent fast
moves while close spacing would
represent slow moves
Jumbling of dots at one point would
indicate fumbling or hesitation of the body member
Used to study the motion pattern as well as to compute
velocity, acceleration and retardation experienced by the
body member at different locations.

CRITICAL EXAMINATION
49
 A systematic and progressive series of
questions with the purpose of determining true
reasons
Based on the reasons, improvements are found
and adopted into a new method, called better
method
The use of questioning technique reduces the
possibility of missing any information which
may be useful for the development of better
method

50
A popular procedure of carrying out critical
examination uses two sets of questions:
Primary questions (answers to these show up the
necessity of carrying out the activity), &
Secondary questions (answers to these allow
considerations to alternative methods of doing the
activity)
Selection of the best way of doing each activity is
later determined to develop new method which is
introduced as a standard practice.

51
PRIMARY QUESTIONS
the PURPOSE for which
the PLACE at which
the SEQUENCE in which
the PERSON by whom
the MEANS by which

52
PURPOSE: what is done?
why is it done?
what else might be done?
what should be done?
PLACE: where is it done?
Why is it done there?
Where else might it is done?
Where should it be done?
SECONDARY QUESTIONS

53
SEQUENCE: When is it done?
Why is it done?
When might it be done?
When should it be done?
PERSON: who does it?
Why does that person do it?
Who else might do it?
Who should do it?
MEANS: How is it done?
Why is it done that way?
How else might it be done?
How should it be done ?

DEVELOPMENT & SELECTION OF IMPROVED METHOD
55
Eliminate all unnecessary operations
Combine operations & elements
Change the sequence of operations
Simplify the necessary operations
Steps in development & selection
Evaluation (evaluate the alternatives)
Investigation (tech. & eco. feasibility)
Selection

PRINCIPLES OF MOTION ECONOMY
56
These principles can be considered under three
different groups;
 Those related to the use of the human body
 Those related to the workplace arrangement
 Those related to the design of tools &
equipment

57
Principles related to the use of human body:
 Both hands should begin and end their basic divisions of activity
simultaneously & should not be idle at the same instant, except
during the rest periods
 Momentum should be employed to assist the worker wherever
possible, and it should be reduced to a minimum if it must be
overcome by muscular effort
 Continuous curved motions should be preferred to straight line
motions involving sudden and sharp changes in the direction
 Work that can be done by the feet should be arranged so that it is
done together with work being done by the hands
 Twisting motions should be performed with the elbows bent

58
Principles related to the arrangement & conditions of workplace:
 Fixed locations should be provided for all tools and
materials so as to permit the best sequence and eliminate
search and select
 Gravity bins and drop delivery should be used to
reduce reach and move times
Use may be made of ejectors for removing finished parts
Work table height should permit work by the operator in
alternately sitting and standing posture
 Glare-free adequate illumination, proper ventilation and
proper temperature should be provided

59

60
Principles related to the design of tools and equipment:
 Use colour, shape or size coding to maximize speed and minimize error
in finding controls
 Use simple on/off, either/or indicators whenever possible
 All levers, handles, wheels and other control devices should be readily
accessible to the operator and should be designed so as to give the best
possible mechanical advantage
 Use quick acting fixture to hold the part/material upon which the work
is being performed
 Use stop guides to reduce the control necessary in positioning motions
 Operating, set-up and emergency controls should be grouped
according to the function

INSTALLATION OF THE PROPOSED METHOD
61
Recommendation phase
Implementation phase

MAINTAIN THE PROPOSED METHOD
62
Follow-up
Monitoring & control
Audit of the savings
Review of the approach
Evaluation of effectiveness of
proposed method

WORK MEASUREMENT / TIME STUDY
63
The application of techniques designed to
establish the time for a qualified worker to carry
out a specified job at a defined level of
performance
Work measurement refers to the estimation of
standard time for an activity, that is the time
allowed for completing one piece of job by using
the prescribed method. Standard time can be
defined as the time taken by an average
experienced worker for the job with provisions for
delays beyond the worker's control.

WORK MEASUREMENT OBJECTIVES
64
Comparing alternative methods
Assessing the correct initial manning
Realistic costing
Delivery date of goods
Cost reduction & cost control
Training new employees
Find ineffective time in a process
Evaluate worker's performance
Facilitate operations scheduling
Establish wage incentive schemes

WORK MEASUREMENT TECHNIQUES
65
For repetitive work (short work cycle) or non-repetitive work;
Time study (stop watch technique)
Work sampling
Synthetic data
Analytical estimating
Predetermined Motion Time Study
(PMTS)
Note - Time study & Work sampling involve direct observation
while remaining are data-based & analytical in nature

66
Techniques Applications Unit of
measurements
Time study Short cycle repetitive jobs.
Widely used for direct work
Centi-minute
(0.01 min)
Work sampling Long cycle jobs Minutes
Synthetic data Short cycle repetitive jobs Centi-minute
Analytical
estimating
Short cycle non-repetitive jobs Minutes
MTM Manual operation confined to
one work centre
TMU (1 TMU =
0.006min)

TIME STUDY PROCEDURE
67
SELECT
OBTAIN & RECORD
DEFINE
MEASURE
EXTEND
DETERMINE
COMPUTE

TIME STUDY – BASIC STEPS
68
a. Obtaining and recording all available information
about the job, operator and the surrounding conditions
likely to affect the execution of the work
b. Recording the complete description of the method,
breaking down the operation into 'elements'
c. Measuring with a stopwatch and recording the
time taken by the operator to perform each element of
the operation
d. Assessing the rating
e. Extending observed time to 'basic times'
f. Determining the allowances to be made over and
above the basic time for the operation
g. Determining the 'standard time' for the operation

TYPES OF ELEMENTS
69
A repetitive element
An occasional element
A constant element
A variable element
A manual element
A machine element
Governing element
A foreign element

TIME STUDY EQUIPMENT
70
There are two methods of timing using
a stop watch. They are:
Fly back or Snap back method
Continuous or Cumulative method

71
1. Fly back Method:
Here the stop watch is started at the beginning of the first element. At
the end of the element the reading is noted in the study sheet. At the
same time, the stop watch hand is snapped back to zero. This is done
by pressing down the knob, immediately the knob is released. The
hand starts moving from zero for timing the next element. Thus the
timing for each element found is called observed time.
2. Continuous method:
Here the stop watch is started at the beginning of the first element.
The watch runs Continuously throughout the study. At the end of each
element the watch readings are recorded on the study sheet. The time
for each element is calculated by successive subtraction. The final
reading of the stop watch gives the total time known as observed
time.

72
Equipments used to measure time using Stop
watch:
 Digital or electronics stop watch
 Electronic data collector and computer
 Observation board
 Observation sheet
 Stationary – Pen, Pencil, Eraser, Calculator

PERFORMANCE RATING
73
Process of adjusting the actual pace of
working of an operator by comparing it with
mental picture of pace of an operator working
at normal speed
Performance rating methods
Speed rating
Westing house method of rating (S,E,C,C)
Synthetic rating (R = P/A)
Objective rating

76
Work sampling (ratio delay study)
A technique of getting facts about utilization of
machines or human beings through a large number
of instantaneous observations taken at random
time intervals.
The ratio of observations of a given activity to
the total observations approximates the percentage
of time that the process is in that state of activity.

77
Work sampling
 Estimates percent of time a worker
spends on various tasks
 Determines how employees allocate
their time
 Used to set staffing levels, reassign
duties, estimate costs, and set delay
allowances

78
Work sampling Procedure
Step 1 . Define the problem.
• Describe the job for which the standard time is to be determined.
• Unambiguously state and discriminate between the two classes of
activities of operator on the job: what are the activities of job that
would entitle him to be in ‘working’ state.
This would imply that when operator will be found engaged in any
activity other than those would entitle him to be in ‘Not Working’
state.
Step 2. Design the sampling plan.
• Estimate satisfactory number of observations to be made.
• Decide on the period of study, e.g. two days, one week, etc.
• Prepare detailed plan for taking the observations.
This will include observation schedule, exact method of observing,
design of observation sheet, route to be followed, particular person
to be observed at the observation time, etc.

79
Work sampling Procedure
Step 3. Contact the persons concerned and take them in
confidence regarding conduct of the study.
Step 4. Make the observations at the pre-decided random
times about the working/not working state of the operator.
When operator is in working state, determine his
performance rating. Record both on the observation
sheet.
Step 5. Obtain and record other information. This
includes operator's starting time and quitting time of the
day and total number of parts of acceptable quality
produced during the day.
Step 6. Calculate the standard time per piece.

80
Predetermined Motion Time Study (PMTS)
A procedure that analyzes any manual
activity in terms of basic or fundamental
motions required to perform it.
Each of these motions is assigned a
previously established standard time value
and then the timings for the individual motions
are synthesized to obtain the total time needed
for performing the activity.

81
Predetermined Motion Time Study (PMTS)
The main use of PMTS lies in the
estimation of time for the performance of a
task before it is performed.
The procedure is particularly useful to
those organizations which do not want
troublesome performance rating to be used
with each study.

82
Applications of PMTS are for
 Determination of job time standards.
 Comparing the times for alternative proposed
methods so as to find the economics of the
proposals prior to production run.
 Estimation of manpower, equipment and space
requirements prior to setting up the facilities and
start of production.
 Developing tentative work layouts for assembly
lines prior to their working in order to minimize the
amount of subsequent re-arrangement and re-
balancing.

83
Some commonly used PMT systems are:
Method Time Analysis
Work Factor
Basic Motion Time
Method Time Measurement

86
MOST WORK MEASUREMENT TECHNIQUE

Work study-150303084338-conversion-gate01

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (11)

Similar to Work study-150303084338-conversion-gate01

Similar to Work study-150303084338-conversion-gate01 (20)

Recently uploaded

Recently uploaded (20)

Work study-150303084338-conversion-gate01